of rare occurrence), we should consider our decisions as pro-
bable only. The probability may appear very great, so that in
affairs of the world we often accept such as certainty, and trust
* Experimental Researches in Electricity, paragraphs 2G57-2681.
1855.] On Mental Education. 483
our welfare or our lives upon it. Still, only an uneducated
mind will confound probability with certainty, especially when
it encounters a contrary conclusion drawn by another from like
data. This suspension in degree of judgment will not make a
man less active in life, or his conclusions less certain as truths ;
on the contrary, I believe him to be the more ready for the
right amount and direction of action on any emergency ; and
am sure his conclusions and statements will carry more weight
in the world than those of the incautious man.
When I was young, I received from one well able to aid a
learner in his endeavours toward self-improvement, a curious
lesson in the mode of estimating the amount of belief we might
be induced to attach to our conclusions. The person was Dr.
Wollaston, who, upon a given point, was induced to offer me a
wager of two to one on the affirmative. I rather impertinently
quoted Butler's well-known lines* about the kind of persons
who use wagers for argument, and he gently explained to me,
that he considered such a wager not as a thoughtless thing, but
as an expression of the amount of belief in the mind of the
person offering it ; combining this curious application of the
wager, as a meter, with the necessity that ever exists of drawing
conclusions, not absolute but proportionate to the evidence.
Occasionally and frequently the exercise of the judgment
ought to end in absolute reservation. It may be very distaste-
ful, and great fatigue, to suspend a conclusion ; but as we are
not infallible, so we ought to be cautious ; we shall eventually
find our advantage, for the man who rests in his position is not
so far from right as he who, proceeding in a wrong direction,
is ever increasing his distance. In the year 1824, Arago dis-
covered f that copper and other bodies placed in the vicinity
of a magnet, and having no direct action of attraction or repul-
sion upon it, did affect it when moved, and was affected by it.
A copper plate revolving near a magnet carried the magnet
with it; or if the magnet revolved, and not the copper, it car-
ried the copper with it. A magnetic needle vibrating freely
over a disc of glass or wood, was exceedingly retarded in its
motion when these were replaced by a disc of copper. Arago
* " Quoth she, I 've heard old cunning stagers
Say fools for arguments use wagers."
t Annales de Chiraie, xxviii. 325.
2 I 2
484 On Mental Education. [1855.
stated most clearly all the conditions, and resolved the forces
into three directions ; but not perceiving the physical cause of
the action, exercised a most wise and instructive reservation as
to his conclusion. Others, as Haldat, considered it as the
proof of the universality of a magnetism of the ordinary kind,
and held to that notion though it was contradicted by the
further facts ; and it was only at a future period that the true
physical cause, namely, magneto-electric currents induced in
the copper, became known to us*. What an education Arago's
mind must have received in relation to philosophical reservation ;
what an antithesis he forms with the mass of table-turners ;
and what a fine example he has left us of that condition of
judgment to which we should strive to attain !
If I may give another illustration of the needful reservation
of judgment, I will quote the case of oxygen and hydrogen
gases, which, being mixed, will remain together uncombined
for years in contact with glass, but in contact with spongy pla-
tinum combine at once. We have the same fact in many forms,
and many suggestions have been made as to the mode of action ;
butasyet we do not know clearly how the result comes to pass.
We cannot tell whether electricity acts or not. Then we should
suspend our conclusions. Our knowledge of the fact itself,
and the many varieties of it, is not the less abundant or sure ;
and when the truth shall hereafter emerge from the mist,
we ought to have no opposing prejudice, but be prepared to
The education which I advocate will require patience and
labour of thought in every exercise tending to improve the
judgment. It matters not on what subject a person's mind is
occupied, he should engage in it with the conviction that it will
require mental labour. A powerful mind will be able to draw
a conclusion more readily and more correctly than one of mode-
rate character ; but both will surpass themselves if they make an
earnest, careful investigation, instead of a careless or prejudiced
one ; and education for this purpose is the more necessary for
the latter, because the man of less ability may, through it, raise
his rank and amend his position. I earnestly urge this point
of self-education, for I believe it to be more or less in the power
of every man greatly to improve his judgment. I do not think
* Philosophical Transactions, 1832, p. 146.
1855.] On Mental Education. 485
that one has the complete capacity for judgment which another
is naturally without. I am of opinion that all may judge, and
that we only need to declare on every side the conviction that
mental education is wanting, and lead men to see that through
it they hold, in a large degree, their welfare and their character
in their own hands, to cause in future years an abundant de-
velopment of right judgment in every class.
This education has for its first and its last step humility. It
can commence only because of a conviction of deficiency ; and
if we are not disheartened under the growing revelations which
it will make, that conviction will become stronger unto the end.
But the humility will be founded, not on comparison of our-
selves with the imperfect standards around us, but on the in-
crease of that internal knowledge which alone can make us
aware of our internal wants. The first step in correction is to
learn our deficiencies, and having learned them, the next step
is almost complete : for no man who has discovered that his
judgment is hasty, or illogical, or imperfect, would go on with
the same degree of haste, or irrationality, or presumption as
before. I do not mean that all would at once be cured of bad
mental habits, but I think betterof humannature than to believe,
that a man in any rank of life, who has arrived at the con-
sciousness of such a condition, would deny his common sense,
and still judge and act as before. And though such self-school-
ing must continue to the end of life to supply an experience of
deficiency rather than of attainment, still there is abundant
stimulus to excite any man to perseverance. What he has lost
are things imaginary, not real ; what he gains are riches before
unknown to him, yet invaluable ; and though he may think more
humbly of his own character, he will find himself at every step
of his progress more sought for than before, more trusted with
responsibility and held in pre-eminence by his equals, and more
highly valued by those whom he himself will esteem worthy of
And now a few words upon the mutual relation of two classes,
namely, those who decline to educate their judgments in regard
to the matters on which they decide, and those who, by self-
education, have endeavoured to improve themselves ; and upon
the remarkable and somewhat unreasonable manner in which
486 On Mental Education. [1855.
the latter are called upon, and occasionally taunted, by the
former. A man who makes assertions, or draws conclusions,
regarding any given case, ought to be competent to investigate
it. He has no right to throw the onus on others, declaring it
their duty to prove him right or wrong. His duty is to demon-
strate the truth of that which he asserts, or to cease from as-
serting. The men he calls upon to consider and judge have
enough to do with themselves, in the examination, correction,
or verification of their own views. The world little knows how
many of the thoughts and theories which have passed through
the mind of a scientific investigator have been crushed in silence
and secrecy by his own severe criticism and adverse examina-
tion ; that in the most successful instances not a tenth of the
suggestions, the hopes, the wishes, the preliminary conclusions
have been realized. And is a man so occupied to be taken from
his search after truth in the path he hopes may lead to its
attainment, and occupied in vain upon nothing but a broad
Neither has the assertor of any thing new a right to claim an
answer in the form of Yes or No ; or think, because none is forth-
coming, that he is to be considered as having established his
assertion. So much is unknown to the wisest man, that he may
often be without an answer : as frequently he is so, because
the subject is in the region of hypothesis, and not of facts. In
either case he has the right to refuse to speak. I cannot tell
whether there are two ^fluids of electricity or any fluid at all.
I am not bound to explain how a table tilts any more than to
indicate how, under the conjurer's hands, a pudding appears
in a hat. The means are not known to me. I am persuaded
that the results, however strange they may appear, are in ac-
cordance with that which is truly known, and if carefully in-
vestigated would justify the well-tried laws of nature ; but, as
life is limited, 1 am not disposed to occupy the time it is made
of, in the investigation of matters which, in what is known to me
of them, offer no reasonable prospect of any useful progress,
or anything but negative results. We deny the right of those
who call upon us to answer their speculations ' if we can,' whilst
we have so many of our own to develope and correct ; and claim
the right for ourselves of withholding either our conclusions or
the reasons for them, without in the least degree admitting that
1855.] On Mental Education. 487
their affirmations are unanswerable. We are not even called
upon to give an answer to the best of our belief; nor bound to
admit a bold assertion because we do not know to the contrary.
No one is justified in claiming our assent to the spontaneous
generation of insects, because we cannot circumstantially ex-
plain how a mite or the egg of a mite has entered into a parti-
cular bottle. Let those who affirm the exception to the general
law of nature, or those others who upon the affirmation accept
the result, work out the experimental proof. It has been done
in this case by Schulze*, and is in the negative; but how few
among the many who make or repeat the assertion, would
have the requisite self-abnegation, the subjected judgment, the
perseverance, and the precision, which has been displayed in
that research !
When men, more or less marked by their advance, are led
by circumstances to give an opinion adverse to any popular
notion, or to the assertions of any sanguine inventor, nothing
is more usual than the attempt to neutralize the force of such
an opinion by reference to the mistakes which like educated
men have made; and their occasional misjudgments and erro-
neous conclusions are quoted, as if they were less competent
than others to give an opinion, being even disabled from judging
like matters to those which are included in their pursuits by
the very exercise of their minds upon them. How frequently
has the reported judgment of Davy, upon the impossibility of
gas-lighting on a large scale, been quoted by speculators en-
gaged in tempting moneyed men into companies, or in the pages
of journals occupied with the popular fancies of the day ; as if
an argument were derivable from that in favour of some special
object to be commended ! Why should not men taught in the
matter of judgment far beyond their neighbours, be expected
to err sometimes, since the very education in which they are
advanced can only terminate with their lives ? What is there
about them, derived from this education, which sets up the
shadow of a pretence to perfection ? Such men cannot learn
all things, and may often be ignorant. The very progress
which science makes amongst them as a body is a continual
correction of ignorance, i. e. of a state which is ignorance in
relation to the future, though wisdom and knowledge in relation
* Miiller's Physiology, or Poggendorff's Annalen, 1836, xxxix. p. 487-
488 On Mental Education. [1855.
to the past. In 1823, Wollaston discovered that beautiful
substance which he called Titanium, believing it to be a simple
metal ; and it was so accepted by all philosophers. Yet this
was a mistake, for Wohler*, in 1850, showed the substance
was a very compound body. This is no reproach to Wollaston
or to those who trusted in him ; he made a step in metallurgy
which advanced knowledge, and perhaps we may hereafter,
through it, learn to know that metals are compound bodies.
Who, then, has a right to quote his mistake as a reproach
against him? Who could correct him but men intellectually
educated as he himself was ? Who does not feel that the in-
vestigation remains a bright gem in the circlet that memory
offers to his honour ?
If we are to estimate the utility of an educated judgment, do
not let us hear merely of the errors of scientific men, which have
been corrected by others taught in the same careful school ;
but let us see what, as a body, they have produced, compared
with that supplied by their reproachers. Where are the
established truths and triumphs of ring-swingers, table-turners,
table- speakers? What one result in the numerous divisions of
science or its applications can be traced to their exertions ?
Where is the investigation completed, so that, as in gas-light-
ing, all may admit that the principles are established and a good
end obtained, without the shadow of a doubt ?
If we look to electricity, it, in the hands of the careful inves-
tigator, has advanced to the most extraordinary results : it
approaches at the motion of his hand ; bursts from the metal ;
descends from the atmosphere ; surrounds the globe : it talks,
it writes, it records, it appears to him (cautious as he has learned
to become) as a universal spirit in nature. If we look to pho-
tography, whose origin is of our own day, and see what it has
become in the hands of its discoverers and their successors,
how wonderful are the results ! The light is made to yield
impressions upon the dead silver or the coarse paper, beautiful
as those it produces upon the living and sentient retina : its
most transient impression is rendered durable for years ; it is
made to leave a visible or an invisible trace ; to give a result
to be seen now or a year hence ; made to paint all natural
forms and even colours ; it serves the offices of war, of peace,
* Annales de Chimie, xxix. p. 166.
1855.] On Mental Education. 489
of art, science, and economy : it replaces even the mind of the
human being in some of its lower services ; for a little camphine
lamp is set down and left to itself, to perform the duty of
watching the changes of magnetism, heat, and other forces of
nature, and to record the results, in pictorial curves, which
supply an enduring record of their most transitory actions.
What has clairvoyance, or mesmerism, or table-rapping done
in comparison with results like these ? What have the snails
at Paris told us from the snails at New York ? What have any
of these intelligences done in aiding such developments ? Why
did they not inform us of the possibility of photography ? or
when that became known, why did they not favour us with
some instructions for its improvement? They all profess to
deal with agencies far more exalted in character than an electric
current or a ray of light : they also deal with mechanical forces ;
they employ both the bodily organs and the mental ; they pro-
fess to lift a table, to turn a hat, to see into a box, or into the
next room, or a town : why should they not move a balance,
and so give us the element of a new mechanical power ? take
cognizance of a bottle and its contents, and tell us how they
will act upon those of a neighbouring bottle ? either see or feel
into a crystal, and inform us of what it is composed? Why
have they not added one metal to the fifty known to mankind,
or one planet to the number daily increasing under the obser-
vant eye of the astronomer ? Why have they not corrected
one of the mistakes of the philosophers ? There are no doubt
very many that require it. There has been plenty of time for
the development and maturation of some of the numerous public
pretences that have risen up in connexion with these supposed
agencies ; how is it that not one new power has been added to
the means of investigation employed by the philosophers, or
one valuable utilitarian application presented to society ?
In conclusion, I will freely acknowledge that all I have said
regarding the great want of judgment manifested by society as
a body, and the high value of any means which would tend to
supply the deficiency, have been developed and declared on
numerous occasions, by authority far above any I possess. The
deficiency is known hypothetically, but I doubt if in reality ;
the individual acknowledges the state in respect of others, but
is unconscious of it in regard to himself. As to the world at
large, the condition is accepted as a necessary fact ; and so it
4-90 On Mental Education. [1855.
is left untouched, almost ignored. I think that education in a
large sense should be applied to this state of the subject, and
that society, though it can do little in the way of communicated
experience, can do much, by a declaration of the evil that exists
arid of its remediable character, by keeping alive a sense of the
deficiency to be supplied, and by directing the minds of men
to the practice and enlargement of that self-education which
every one pursues more or less, but which under conviction
and method would produce a tenfold amount of good. I know
that the multitude will always be behindhand in this education,
and to a far greater extent than in respect of the education
which is founded on book learning. Whatever advance books
make, they retain ; but each new being comes on to the stage
of life, with the same average amount of conceit, desires, and
passions, as his predecessors, and in respect of self-education
has all to learn. Does the circumstance that we can do little
more than proclaim the necessity of instruction, justify the igno-
rance, or our silence, or make the plea for this education less
strong ? Should it not, on the contrary, gain its strength from
the fact that all are wanting more or less ? I desire we should
admit that, as a body, we are universally deficient in judgment.
I do not mean that we are utterly ignorant, but that we have
advanced only a little way in the requisite education, compared
with what is within our power.
If the necessity of the education of the judgment were a
familiar and habitual idea with the public, it would often afford
a sufficient answer to the statement of an ill-informed or in-
competent person ; if quoted to recall to his remembrance the
necessity of a mind instructed in a matter, and accustomed to
balance evidence, it might frequently be an answer to the in-
dividual himself. Adverse influence might, and would, arise
from the careless, the confident, the presumptuous, the hasty,
and the dilatory man, perhaps extreme opposition ; but I believe
that the mere acknowledgment and proclamation of the igno-
rance, by society at large, would, through its moral influence,
destroy the opposition, and be a great means to the attainment
of the good end desired : for if no more be done than to lead
such to turn their thoughts inwards, a step in education is
gained : if they are convinced in any degree, an important ad-
vance is made; if they learn only to suspend their judgment,
the improvement will be one above price.
1855.] On Mental Education. 491
It is an extraordinary thing, that man, with a mind so won-
derful that there is nothing to compare with it elsewhere in the
known creation, should leave it to run wild in respect of its
highest elements and qualities. He has powers of comparison
and judgment, by which his final resolves, and all those acts
of his material system which distinguish him from the brutes,
are guided : shall he omit to educate and improve them when
education can do much ? Is it towards the very principles and
privileges that distinguish him above other creatures, he should
feel indifference ? Because the education is internal, it is not
the less needful; nor is it more the duty of a man that he
should cause his child to be taught than that he should
teach himself. Indolence may tempt him to neglect the
self-examination and experience which form his school, and
weariness may induce the evasion of the necessary practices ;
but surely a thought of the prize should suffice to stimulate
him to the requisite exertion : and to those who reflect upon
the many hours and days, devoted by a lover of sweet sounds,
to gain a moderate facility upon a mere mechanical instrument,
it ought to bring a correcting blush of shame, if they feel con-
victed of neglecting the beautiful living instrument, wherein
play all the powers of the mind.
I will conclude this subject : believe me when I say I have
been speaking from self- conviction. I did not think this an
occasion on which I ought to seek for flattering words regard-
ing our common nature ; if so, I should have felt unfaithful to
the trust I had taken up ; so I have spoken from experience.
In thought I hear the voice, which judges me by the precepts
I have uttered. I know that I fail frequently in that very
exercise of .judgment to which I call others; and have abun-
dant reason to believe that much more frequently I stand
manifest to those around me, as one who errs, without being
corrected by knowing it. I would willingly have evaded ap-
pearing before you on this subject, for I shall probably do but
little good, and may well think it was an error of judgment to
consent: having consented, my thoughts would flow back
amongst the events and reflections of my past life, until I found
nothing present itself but an open declaration, almost a con-
fession, as the means of performing the duty due to the subject
and to you.
N.B. A dash rule represents the italics immediately preceding it.
ACOUSTICAL figures, peculiar, 314.
Aerial perspective, 215.
Air excluded from ice, 373.
Alkali in glass, its effect, 281.
Alkaline change of vegetable colours,
Alloys of iron, 80.
Alloys of steel, 57, 68.
Aluminium and polarized light, 441.
Aluminium deflagrations, 405.
Ammonia, cases of its formation, 143.
, its pressure, 114.
, liquefied, 94, 114, 127.
, solidified, 114.
, compounds with chtorides, 18.
, solutions of silver in, 13.
Ammonio-fulminating silver, 16.
Anhydrous sulphate of soda, 230.
Arseniuretted hydrogen, liquefied, 115,
, its pressure, 115.
Bicarburet of hydrogen, 157.
Boracic acid, its action on turmeric, 27-
Bottles replaced by tubes, 152.
Breathing time extended, 358.
Bromides of phosphorus, 104.
Capillary tubes and gases, 5, 6.
Carbon, chlorides of, 33.
Carbon and hydrogen, new compounds
Carbonic acid, liquefied, 92, 108, 121,
-, solidified, 102, 108.
, its freezing- and boiling-points,
, liquid, its pressure, 109.
, solid, electric, 102.
Carburet of hydrogen, new, 163.
Chemical force and conservation of force,
Chloride of silver and ammonia, 18, 94.
decomposed by hydrogen, 31.
Chlorides of carbon, 33, 53.
Chlorides combined with ammonia, 18.
Chlorine, hydrated, 81.
Chlorine gas condensed, 84, 85, 95, 129,
Cohesion, its effect in solids and fluids,
, its relation to ice and water, 378.
, in relation to saline crystals, 380.
Cold baths for gases, 99.
Combustion of the diamond, 11.
Condensation gauges, 91, 98.
Condensation of gases, 89, 96.
, ammonia, 94, 114, 127.
, arseniuretted hydrogen, 115, 130.
, carbonic acid, 92, 108, 121, 124,
, chlorine, 85, 95, 129, 131.
, cyanogen, 94, 113.
, euchlorine, 92, 110.
, fluosilicon, 104.
, hydriodic acid, 103.
, hydrobromic acid, 104.
, hydrochloric acid, 95, 106, 131.
, nitrous oxide, 93, 111, 117.
, oil-gas, 133.
, olefiant gas, 102, 118.
, oxygen attempted, 122.
, phosphuretted hydrogen, 105.
, sulphuretted hydrogen, 90, 107.